A communication network may communicate information using optical signals transmitted as light pulses. Certain devices of a communication network may include optical modulators that modulate the optical signals. Optical modulators are typically biased at bias points. A bias point, however, may drift due to, for example, temperature variation. Known bias point monitoring techniques may measure the optical power of a signal to monitor the bias point of an optical modulator. These known techniques, however, are not satisfactory in certain situations.